| =pod |
| |
| =head1 NAME |
| |
| RSA-PSS - EVP_PKEY RSA-PSS algorithm support |
| |
| =head1 DESCRIPTION |
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| The B<RSA-PSS> EVP_PKEY implementation is a restricted version of the RSA |
| algorithm which only supports signing, verification and key generation |
| using PSS padding modes with optional parameter restrictions. |
| |
| It has associated private key and public key formats. |
| |
| This algorithm shares several control operations with the B<RSA> algorithm |
| but with some restrictions described below. |
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| =head2 Signing and Verification |
| |
| Signing and verification is similar to the B<RSA> algorithm except the |
| padding mode is always PSS. If the key in use has parameter restrictions then |
| the corresponding signature parameters are set to the restrictions: |
| for example, if the key can only be used with digest SHA256, MGF1 SHA256 |
| and minimum salt length 32 then the digest, MGF1 digest and salt length |
| will be set to SHA256, SHA256 and 32 respectively. |
| |
| =head2 Key Generation |
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| By default no parameter restrictions are placed on the generated key. |
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| =head1 NOTES |
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| The public key format is documented in RFC4055. |
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| The PKCS#8 private key format used for RSA-PSS keys is similar to the RSA |
| format except it uses the B<id-RSASSA-PSS> OID and the parameters field, if |
| present, restricts the key parameters in the same way as the public key. |
| |
| =head1 CONFORMING TO |
| |
| RFC 4055 |
| |
| =head1 SEE ALSO |
| |
| L<EVP_PKEY_CTX_set_rsa_pss_keygen_md(3)>, |
| L<EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md(3)>, |
| L<EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(3)>, |
| L<EVP_PKEY_CTX_new(3)>, |
| L<EVP_PKEY_CTX_ctrl_str(3)>, |
| L<EVP_PKEY_derive(3)> |
| |
| =head1 COPYRIGHT |
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| Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved. |
| |
| Licensed under the OpenSSL license (the "License"). You may not use |
| this file except in compliance with the License. You can obtain a copy |
| in the file LICENSE in the source distribution or at |
| L<https://www.openssl.org/source/license.html>. |
| |
| =cut |